1. Technical Field
The present invention relates to an aluminum metal line of a semiconductor device, and a method of fabricating the same.
2. Description of the Related Art
A metal line of the related art semiconductor device is generally formed by an aluminum (Al) line process. When the aluminum line process technology is used in which the critical dimension (CD) of the line is 130-nanometers (nm), many problems may occur.
In semiconductor devices with 130 nm aluminum lines, the CD of the aluminum line and the distance between the aluminum lines become very small. The CD of the aluminum line is 0.15 micrometers (μm), and the distance between the aluminum lines is 0.17 μm. Even though the aluminum lines must maintain small electric resistance because of its characteristics, such a fine CD in such a fine structure of the aluminum lines may cause an undesirable increase in electric resistance.
In a photolithography process of 130 nm aluminum line process, photoresist (PR) on the CD collapses because of the fine CD of the aluminum lines. The collapse of the PR causes a short of the aluminum lines.
An intermetallic dielectric (IMD) process for gap filling between the aluminum lines reaches a limit, and voids are generated by the defective gap filling. Therefore, the aluminum line is formed with a great thickness, so that the electric resistance can be reduced even if the CD value of the aluminum line is small. However, in this case, it is difficult to implement a narrow aluminum line with a thick profile.